AM fungi could be also considered an effective tool in the protection of root apparatus from Al phytotoxicity in acidic soils (Marschner, 1995). In fact, Danielson (1985), Clark (1997), and Cumming and Ning (2003), reported that AM fungi are widely established in low pH soils and colonization of plant roots by AM often, but not always enhances the crop performance on such soils by improving nutrient uptake and assimilation under Al stress con- ditions.